The invention relates to a water supplying device of a hand-held power tool, in particular for supplying a cutting wheel of a cut-off machine with water. The water supplying device comprises a water-conveying line and a valve arrangement arranged in the line for controlling a water flow through the line. The valve arrangement comprises a control valve with a valve body adjustable across a positioning travel.
The invention also relates to an arrangement for actuating a water supplying device of a hand-held power tool for actuating a device for supplying water of the aforementioned kind, the arrangement comprising an actuator acting on the valve arrangement.
Hand-held power tools comprising a water supply through which, for example, cooling water is supplied to the tool of the power tool and/or to the workpiece are known. Particularly in the case of a hand-held cut-off machine, the cutting wheel can be supplied with water for binding dust produced when performing a cut.
The control or regulation of the supplied amount of water is not satisfactory in the known embodiments. By means of an external valve, the water flow can be released before beginning the work to be performed and can be interrupted after completion. After release of the water flow, the water flows to the location to be worked on even when the power tool is not in operation. Before and after the actual working steps as well as during short work interruptions, unwanted quantities of water escape that, in addition to increasing water usage, also compromise the location to be worked on with an unnecessary quantity of water.
U.S. Pat. No. 6,442,841 B1 discloses an arrangement with a device for supplying water to a hand-held power tool in which a shut-off valve for opening or closing a water line is provided. The shut-off valve is actuatable by means of a throttle trigger lock with which also the throttle trigger for adjusting the output of the drive motor can be released. By actuating the throttle trigger lock, a water supply is provided only when readiness to operate the power tool with power is indicated by releasing the throttle trigger.
A disadvantage of the disclosed arrangement is that, for example, when opening the throttle for warming up the drive motor during cold start, water can be released even when no working process is to be performed. Adjustment of the water flow rate is difficult as is the adjustment in regard to different water pressure available at the intake. Coupling the throttle trigger lock to the shut-off valve causes the basic function of the power tool, such as simple acceleration or performing a dry cut, to be made difficult when the valve is dirty, stiff and/or damaged.
It is an object of the present intention to provide a water supplying device of a hand-held power tool that enables improved adjustment of the conveyed amount of water to the actual water demand.
The invention further has the object to provide an arrangement for actuating the aforementioned device which arrangement enables an improved control of the water supply.